Pull up bar attachment



FIG. 1 is a top, front, left perspective view of a pull up bar attachment showing our new design;

FIG. 2 is a top, rear, right perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines in the drawings show portions of the pull up bar attachment that form no part of the claimed design. 

CLAIM The ornamental design for a pull up bar attachment, as shown and described. 